Potential New Treatment for Liver Cancer

Worldwide, liver cancer is the third cause of death caused by cancer, falling in behind lung (1.4 million deaths) and stomach cancer (740,000 deaths) at around 700,000 deaths. For the first time, researchers have discovered a special type of molecular regulator called a micro-RNA (miR-124) that could be used someday as a treatment for liver cancer. The same team also found a mechanism in mice that ultimately causes normal liver cells to transform into cancerous ones. In this new study, mice were exposed to a cancer-causing chemical called DEN, which triggered a circuit of inflammation in the liver that ultimately led to cancer. The investigators identified one element of the circuit called miR-124. Molecules in this class have been associated with different types of cancer. Another key player in the circuit is HNF4α, a substance that has an important role in the formation of liver cells and their function. If HNF4α is suppressed, the result can be inflammation, which can then lead to cancer. 

Scientists hope that “miR-124 potentially could be sued as a preventive in patients at high risk of liver cancer because they have chronic hepatitis C or as a therapeutic agent in patients with liver cancer.” They plan to begin a phase I clinical trial to explore this possible new liver cancer treatment in 2012.

Organ Transplants and Cancer Risk

“While transplantation is a life-saving therapy for patients with end-stage organ disease, it also puts recipients at an increased risk for developing cancer, in part because of medications administered to suppress the immune system and prevent rejection of the organ,”. Organ transplant recipients have a high risk of developing 32 different types of cancer, according to a new study. Future research to understand why may lead to better strategies for preventing cancer among transplant recipients.

In 2010, over 28,000 organ transplantations were performed in the U.S., including 16,899 kidney, 6,291 liver, 2,333 heart and 1,770 lung transplants. Transplant recipients are known to be at a higher risk for developing cancer than the general population. The researchers found a twofold overall increased risk of cancer among transplant recipients. They noted elevated risk for 32 different types of cancer, some known to be related to infectious agents (such as anal cancer and Kaposi sarcoma) and others unrelated to infections (such as melanoma and thyroid cancer). The most common cancers among transplant recipients were non-Hodgkin lymphoma (14% of all cancers in transplant recipients), lung cancer (13%), liver cancer (9%) and kidney cancer (7%). The risk of cancer was affected by the type of transplant. Lung cancer risk, for example, was highest in lung recipients. 

Targeted Light Therapy Destroys Cancer Cells - photoimmunotherapy

Scientists have developed a noninvasive technique that uses light to selectively wipe out cancerous cells in mice without harming surrounding tissue. With further research, this novel method might eventually be used to treat tumors in humans. The 3 major types of cancer therapy—surgery, radiation and chemotherapy—effectively destroy cancerous tissues, but tend to damage normal tissue as well. Researchers have long sought therapies that can zero in on tumor cells and leave neighboring healthy cells intact. One targeted technique, available for over a decade, is called monoclonal antibody (mAb) therapy. These antibodies destroy cancer cells by latching onto specific proteins on the cell surface. Researchers can also attach a deadly payload for mAbs to carry to target cells. Over 25 therapeutic mAbs have been approved by the US Food and Drug Administration to date. But current mAb therapies often require repeated doses at levels that can cause serious side effects. The unique method, called photoimmunotherapy, was described in the November 6, 2011, online edition of Nature Medicine.

After evaluating several light-sensitive molecules, the researchers settled on a fluorescent dye called IR700, which is activated by near infrared light. They chemically linked IR700 to 3 different mAbs. One antibody targets HER2, a cell-surface molecule that's expressed at high levels by some breast cancer cells. Another binds to EGFR, a receptor molecule prevalent on some lung, pancreatic and colon cancer cells. The third mAb homes in on PSMA, a molecule overexpressed by prostate cancer cells. The researchers found that the mAb-IR700 complexes effectively attached to cultured cancer cells. When exposed to near-infrared light, the targeted cells rapidly died. In contrast, cells that weren't bound by the complexes were unharmed. Mice with cancer were injected with the mAb-IR700 that targets EGFR. The animals showed dramatic tumor shrinkage after even a single dose of near-infrared light. The treatment appeared to be safe, with no signs of toxicity.

Other photosensitizing molecules have been used to treat cancer in the past. But these conventional, untargeted photosensitizers can damage both healthy and cancerous tissue. In addition, the type of light needed to activate these molecules can penetrate through less than 1 cm of tissue (about a third of an inch). The near-infrared light used to activate IR700 can penetrate tissue to a depth of several centimeters, more than an inch. Low doses of mAb-IR700 can also help identify cancerous cells in tissues, because the complex emits a small amount of light. As treated tumors shrank, their fluorescence dimmed and eventually disappeared.

Drinking Tea reduces risk of breast cancer by 37%

A newly released study has found that drinking tea results in a 37% reduction in breast cancer risk for women under the age of 50, an age in which breast cancer can be particularly virulent. Another recent study has shown that tea drinking reduces risk of endometrial cancer. These results add to the pile of data showing tea is one of the healthiest beverages a person can drink.Whether it is Black, Green, White or Oolong, tea is the world's second most commonly consumed beverage. Tea provides potent flavonoids and antioxidants. Tea is a research superstar against cancer.Tea drinking has been shown to play an important role in human cancer reduction by inhibiting uncontrolled cell growth, known as cell proliferation, and by promoting appropriate programmed cell death, known as apoptosis. Epigallocatechin gallate (EGCG), an abundant polyphenol in green tea, may protect normal cells from carcinogens as well as eliminate cancer cells through promotion of apoptosis. The major polyphenols of black tea and green tea have been shown to inhibit proteins which are closely associated with tumor growth and metastasis. Black tea polyphenols have also been shown to prevent oxidative DNA damage to colon mucosa.

What are Proto-Oncogenes and Tumor-Suppressor Genes?

1. Two broad classes of genes—proto-oncogenes (e.g., ras) and tumor-suppressor genes (e.g., APC) play a key role in cancer induction. These genes encode many kinds of proteins that help control cell growth and proliferation; mutations in these genes can contribute to the development of cancer. 2. Most cancers have inactivating mutations in one or more proteins that normally function to restrict progression through the G1 stage of the cell cycle (e.g., Rb and p16). Virtually all human tumors have inactivating mutations in proteins such as p53 that normally function at crucial cell-cycle checkpoints, stopping the cycle if a previous step has occurred incorrectly or if DNA has been damaged. Likewise, a constitutively active Ras is found in several human tumors of different origin. Thus normal growth control and malignancy are two faces of the same coin. 3. An oncogene is any gene that encodes a protein able to transform cells in culture or to induce cancer in animals. 4. Of the many known oncogenes, all but a few are derived from normal cellular genes (i.e., proto-oncogenes) whose products participate in cellular growth-controlling pathways. For example, the ras gene is a proto-oncogene that encodes an intracellular signal-transduction protein; 5. Conversion, or activation, of a proto-oncogene into an oncogene generally involves a gain-of-function mutation. 6. Tumor-suppressor genes generally encode proteins that in one way or another inhibit cell proliferation. Loss of one or more of these “brakes” contributes to the development of many cancers. 7. Five broad classes of proteins are generally recognized as being encoded by tumorsuppressor genes: • Intracellular proteins, such as the p16 cyclin-kinase inhibitor, that regulate or inhibit progression through a specific stage of the cell cycle • Receptors for secreted hormones (e.g., tumor derived growth factor ?) that function to inhibit cell proliferation • Checkpoint-control proteins that arrest the cell cycle if DNA is damaged or chromosomes are abnormal • Proteins that promote apoptosis and Enzymes that participate in DNA repair.

What are the Types of Cancer?

1. Carcinoma: It includes tumors of brain, breast, skin, cervical region. These are derived from epithelial tissue, originating from either ectoderm or endoderm. Theseoccurs as solid tumors, located in the nervous tissue on the body surface or associated glands.
2. Sarcoma: They are the cancers of connective tissues, cartilage, bone or muscles which are mesodermal in origin.
3. The leukemias: A class of sarcomas, grow as individual cells in the blood, whereas most other tumors are solid masses. (The name leukemia is derived from the Latin for “white blood”: the massive proliferation of leukemic cells can cause a patient’s blood to appear milky)
4. Lymphoma: Lymph nodes, bone marrow, liver and spleen produces excessive lymphocytes. Cancer in them are called as lymphomas eg. Hodgkin’s disease.

A simple overview of Cancer and Malignant growth

Cancer is a disease of the body’s cells. It occurs when cells in the body become abnormal and grow out of control. A change which makes the gene faulty is called a mutation. Some special genes, called control genes, instruct the cell to copy its genes correctly, and to divide in an orderly manner. They stop controlling cell division, which is cancer.
Benign Tumors: Tumors arise with great frequency, especially in older animals and humans, but most pose little risk to their host because they are localized and of small size. The surface interaction molecules that hold tissues together keep benign tumor cells, like normal cells, localized to appropriate tissues. A fibrous capsule usually delineates the extent of a benign tumor.
Malignant tumor: In contrast, the cells composing a malignant tumor, or cancer, express some proteins characteristic of the cell type from which it arose, and a high fraction of the cells grow and divide more rapidly than normal. Some malignant tumors remain localized and encapsulated, at least for a time; an example is carcinoma in situ in the ovary or breast. Most, however, do not remain in their original site; instead, they invade surrounding tissues, get into the body’s circulatory system, and set up areas of proliferation away from the site of their original appearance. The spread of tumor cells and establishment of secondary areas of growth is called metastasis; most malignant cells eventually acquire the ability to metastasize. Thus the major characteristics that differentiate metastatic (or malignant) tumors from benign ones are their invasiveness and spread. They are usually less well differentiated than normal cells or benign tumor cells. The presence of invading cells is the most diagnostic indication of a malignancy. Cancer cells can multiply in the absence of growth-promoting factors required for proliferation of normal cells and are resistant to signals that normally program cell death (apoptosis). Both primary and secondary tumors require angiogenesis, the recruitment of new blood vessels, in order to grow to a large mass. Cancer cells, which are closer in their properties to stem cells than to more mature differentiated cell types, usually arise from stem cells and other proliferating cells.
Following are the types of Cancer:
1. Carcinoma: It includes tumors of brain, breast, skin, cervical region. These are derived from epithelial tissue, originating from either ectoderm or endoderm. These occurs as solid tumors, located in the nervous tissue on the body surface or associated glands.
2. Sarcoma: They are the cancers of connective tissues, cartilage, bone or muscles which are mesodermal in origin.
3. The leukemias: A class of sarcomas, grow as individual cells in the blood, whereas most other tumors are solid masses. (The name leukemia is derived from the Latin for “white blood”: the massive proliferation of leukemic cells can cause a patient’s blood to appear milky)
4. Lymphoma: Lymph nodes, bone marrow, liver and spleen produces excessive lymphocytes. Cancer in them are called as lymphomas eg. Hodgkin’s disease.